a) Field of the Invention
The present invention relates to a motor/generator unit having a motor/generator constructed so as to be enabled to give and receive a torque to and from rotary elements of a torque converter interposed between an engine and a transmission.
b) Description of the Related Art
Recently, in automotive vehicles, a fuel economy improvement has been demanded from standpoints of environment protection and limited resources.
One of techniques to improve the fuel economy includes a motor/generator installation in a vehicular engine driving force transmission system. For example, the motor/generator performs a regeneration such as to convert a running energy into an engine torque by means of an output torque of the motor/generator.
A Japanese Patent Application First Publication No. Heisei 7-123509 published on May 12, 1995 exemplifies a first previously proposed motor/generator unit.
A Japanese Patent Application First Publication No. Heisei 10-225058 published on Aug. 21, 1998 exemplifies a second previously proposed motor/generator unit.
In the first previously proposed motor/generator unit, the motor/generator is installed so as to be enabled to give and receive the torque to and from an output axle of the engine. If a power margin is left in a vehicular battery power, the motor/generator is caused to function as a motor to assist a driving force of the engine. During a braking, the motor/generator is caused to function as a power generator to regenerate the power from the running energy in a range not exceeding a battery power. Using a conventional power train of the vehicle, the fuel economy improvement is, thus, made.
The second previously proposed motor/generator unit has been applied to, so-called, a hybrid vehicle. The hybrid vehicle includes the engine, a clutch motor, and an assistance motor, drives of these engine and motors being controlled to be enabled to carry out efficient operations of the generation of the running energy, the power generation during the vehicular run, and the regeneration during the braking.